1. Field of the Invention
The present invention relates to a door lock assembly, and more particularly to a door lock assembly having a safety and anti-theft structure.
2. Description of the Prior Art
Various kinds of typical door lock assemblies have been developed for anti-theft purposes. However, some of the door locks may also lock the doors for preventing the door from being easily opened from inside of the house buildings. When fires happened, the users may also be locked inside the house building and may not easily escape from the house building.
The other door locks may be easily unlocked by the unauthorized persons by engaging a planer member into the slit formed between the door panel and the door frame or the wall, and by moving or actuating the latch inward of the lock device by the planer member, from outside of the house buildings.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional door lock assemblies.
The primary objective of the present invention is to provide a door lock assembly including a safety and anti-theft structure for preventing the door from being opened from outside, and for allowing the door to be easily opened from inside of the house building.
In accordance with one aspect of the invention, there is provided a door lock assembly for a door panel, the door lock assembly comprising a striker plate including a cavity formed therein, a base, a latch rotatably supported on the base with a pivot shaft, and including a front portion extendible outward of the base and engageable into the cavity of the striker plate, for locking the door panel, and a locking device provided for locking the latch to the base, to prevent the latch from being rotated relative to the base.
The base includes a fence extended therefrom and having an opening for rotatably receiving the latch. The latch includes a chamber for receiving a pawl of the locking device which has a first end pivotally secured to the latch with an axle and which has a second end, and a tongue provided on the second end of the pawl, and a biasing device provided for biasing the tongue of the pawl to engage with the base and to lock the latch to the base.
The latch includes a first end having a notch formed by two ears, for receiving the first end of the pawl, the axle is engaged through the first end of the pawl and the ears of the latch. The base includes a bulge for engaging with the tongue and for locking the latch to the base.
A limiting device is further provided for limiting the pawl to move relative to the latch, and includes a beam engaged through the chamber of the latch, and engageable with the pawl, for preventing the pawl from moving out of the chamber of the latch.
A disengaging device is further provided for disengaging the tongue of the pawl from the base, and includes a spring for biasing the tongue of the pawl away from the base.
The disengaging device includes a bar having a first end pivotally secured to the base, and having a second end engaged with the pawl, the spring is engaged between the second end of the bar and the base.
A limiting device is further provided for limiting a movement of the bar relative to the base and includes a catch pivotally supported on the base, and having a pair of recesses formed therein for selectively receiving the bar.
The bar is retained in a lower position when the bar is received in a first of the recesses of the catch, and in a higher position when the bar is received if a second of the recesses of the catch.
The disengaging device includes a lever pivotally secured to the base with a rod, and having a first end engaged with the pawl for moving the pawl inward the chamber of the latch. The lever includes a second end having a hand grip for rotating the lever and for forcing the first end of the lever to move the pawl inward the chamber of the latch.
The disengaging device includes a forcing device provided for forcing the first end of the lever to move the pawl inward the chamber of the latch, and having an actuator rotatably supported in the base and having at least one actuating surface formed therein and engaged with the first end of the lever.